Recent giant impact models focus on producing a circumplanetary disk of the proper composition around the Earth and defer to earlier works for the accretion of this disk into the Moon. The discontinuity between creating the circumplanetary disk and accretion of the Moon is unnatural and lacks simplicity. In addition, current giant impact theories are being questioned due to their inability to find conditions that will produce a system with both the proper angular momentum and a resultant Moon that is isotopically similar to the Earth. Here we return to first principles and produce a continuous model that can be used to rapidly search the vast impact parameter space to identify plausible initial conditions. This is accomplished by focusing on the three major components of planetary collisions: constant gravitational attraction, short range repulsion and energy transfer. The structure of this model makes it easily parallelizable and well-suited to harness the power of modern Graphics Processing Units (GPUs). The model makes clear the physically relevant processes, and allows a physical picture to naturally develop. We conclude by demonstrating how the model readily produces stable Earth–Moon systems from a single, continuous simulation. The resultant systems possess many desired characteristics such as an iron-deficient, heterogeneously-mixed Moon and accurate axial tilt of the Earth.

Journal of Astrophysics and Astronomy | News

Continuous Article Publication

Posted on January 27, 2016

Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.